1. Technical Field
Various implementations relate to a nonvolatile memory device, and more particularly, to a variable resistance memory device and a method of manufacturing the same.
2. Related Art
In recent years, with demands on semiconductor devices with high performance and low power, next generation semiconductor memory devices with non-volatility and non-refresh have been researched. As one of the next-generation semiconductor memory devices, variable resistance memory devices are suggested, and there are phase-change random access memory devices (PCRAMs), resistive RAMs (ReRAMs), magnetic RAMs (MRAMs), spin-transfer torque magnetoresistive RAMs (STTMRAMs), or polymer RAMs (PoRAMs), as the variable resistance memory devices.
The variable resistance memory devices perform a memory operation to have a set state or a reset state by controlling a phase-change material, which constitutes a data storage unit, to a crystalline state or an amorphous state.
Attempts to reduce a reset current, that is, a current required to switch a phase-change material to an amorphous state in PCRAMs have been made. Reduction in the reset current of the PCRAMs may be determined by a resistance of the phase-change material layer and a contact area between a lower electrode and the phase-change material layer.
Thus, at present, attempts to reduce the contact area between the lower electrode and the phase-change material layer, which can be controlled by a process, have been made increasingly.